1. Technical Field
The invention relates to a print control method and a printing system, and more particularly to a method for controlling a printing unit operating on a battery.
2. Description of the Related Art
Recently, as digital cameras are used widely, photographic printing by using printers is realized everywhere. Conventional printers generally consume electric power from building electric wiring, and cannot be used outdoors, and since power cords must be plugged and unplugged, and it is hard and complicated to move the place of installation. In such circumstance, it seems there is a considerable latent need for printing operating on batteries. However, as far as batteries are used as power source, the operating time is determined by the remainder of battery, the user cannot use the printer safely unless the remaining capacity of battery is known. Methods of detecting the remaining capacity of battery are known, for example as disclosed in JP-A-9-171065. If, however, the remaining capacity of battery is known, it is extremely difficult to know how many pages can be printed more at a certain remaining capacity of battery.
JP-A-2003-48327 discloses a printer capable of displaying the number of pages that can be printed depending on the remainder of the ink as coloring material (the number of remaining printable copies). With such printer, the user can print safely without fear of running out of ink in the midst of printing if the ink remainder becomes small.
JP-A-2002-283670 discloses a printing system in which the total number of pages to be printed and the number of remaining printable copies specified by the remainder of the ink as coloring material are compared when printing of pages is instructed, and printing is stopped by outputting an alarm when the number of remaining printable pages is smaller than the total number of pages to be printed. The total number of pages to be printed corresponds to the product of the number of pages per copy and the number of copies. According to such printing system, the user knows whether printing is completed until the end before starting printing, so that the printer can be used safely without fear of running out of the ink in the midst of operation.